Biden was just trying to keep things focused on positive things for July 4th, which isn't out of bounds since it's the holiday where we celebrate America.
I was watching the thing, and there was nothing to it. He said he'd have another press conference in a few days and address reporters' concerns about Afghanistan, which he said were legitimate questions (correcting himself after calling them "negative.")
As for leaving Afghanistan... whenever we left there people would say we were leaving at the wrong time. There never was a right time to leave it, and there never will be. Were it up to me I'd pull our troops out, but maintain a strong air presence and whenever the Taliban regrouped I'd just bomb the mother-of-all-fucks out of them, but I've never been a pacifist when it comes to terrorists. But then I'd be bombing militia compounds of white-supremacist terrorists in America, too. I like making scumbags dead. That's why nobody'd vote for me... probably for the best.
As for if we should have ever gone there, I was fine with us going to Afghanistan, because Bin Ladin was there and it was his mutts who attacked us. It was going into Iraq that was idiotic.